Los Angeles: Researchers at the University of Southern California have developed an innovative method for upcycling carbon fibres used in aerospace, significantly reducing landfill waste and energy consumption compared to traditional recycling processes, while maintaining high performance and promoting sustainability in the industry.
Researchers at the University of Southern California (USC) have announced significant advancements in the upcycling of high-performance composite materials, particularly in the area of carbon fibers used in the aerospace industry. This study, led by professor Travis Williams from the Dornsife College of Letters, Arts and Sciences, aims to address the critical issue of waste generated by aircraft at the end of their life cycle.
Carbon fibres, known for their strength and light weight, are crucial components in the construction of planes and cars, consisting of multiple layers woven together with a robust epoxy resin. However, Williams pointed out the challenges associated with recycling these materials, noting that conventional methods often leave 99.1% of the composite materials ending up in landfills due to the expensive and complicated recycling processes. “Trying to un-thermoset a thermoset, un-epoxy an epoxy, is like trying to unboil an egg,” he explained, emphasising the difficulty of separating the carbon fibres from the epoxy.
In a promising development, the research team has pioneered a method that can chemically detach the epoxy while preserving the integrity of the carbon fibres, allowing them to be reused. Williams stated, “We started inventing reactions to do that for the different kinds of epoxies and different kinds of thermosets that they use in aviation. It worked in a number of cases … you can get it back, still woven as fabric, and nobody else has been able to do that.”
The study’s findings have captured the attention of the materials science community, creating a surge of interest in the potential for new applications of recycled materials. Justin Lim, a doctoral student involved in the study, commented, “I would argue that our method is superior to other methods out there in the literature today,” further asserting the focus on sustainable methods.
Ding-Yuan Lim, another graduate student participating in the research, shared insights into the cost-effectiveness of their approach, highlighting the use of common chemical reagents to reduce expenses and enhance safety. Traditional recycling processes often require extreme conditions, such as high temperatures and pressures, making them less practical and more hazardous.
The upcycling method developed at USC reportedly consumes between 10.8 to 36 megajoules of energy per kilogram, a stark contrast to the energy-intensive production of new carbon fibres, which ranges from 198 to 594 megajoules per kilogram. Madison Fette, also a graduate student in the chemistry department, noted that the cost of upcycling is significantly lower, only one-fifth of what is needed to create new fibres.
In addition to environmental benefits, the recycled carbon fibres demonstrate superior properties, being lighter, stronger, and stiffer than aluminium. As Williams noted, aircraft constructed from these materials would use 20% less fuel, leading to substantial reductions in CO2 emissions.
The researchers have conducted extensive tensile tests showing that the mechanical properties of the upcycled fibres are almost identical to those of original fibres, maintaining at least 90% of their original strength. However, Williams expressed concern over perceptions within the manufacturing community regarding the quality of recycled materials, stating, “What’s going to kill us is … the manufacturing community who seem to believe that recycled [fiber] is lower quality.”
Regarding potential future impacts on policies affecting the materials industry, Williams speculated about the implications of national energy priorities, suggesting that shifts under the current administration could support the transition towards modern materials like composites.
This pioneering research at USC highlights the development of innovative practices in recycling and composite material production, which could transform the aerospace and automotive industries while promoting sustainability.
Source: Noah Wire Services
